Method for lifting of magmatic lava to the surface

ABSTRACT

Invention relates to the mining industry and may be used for magmatic lava extraction. Technical result of the invention is improvement of efficiency, safety, steadiness and controllability of the lava lifting operation. Essence of the invention: method of lava lifting to the surface is characterized by application of carrier pipe for the lava lifting and a smaller diameter pipe for injection of incombustible gas, connected to the carrier pipe by the dispenser on specified depth. Length of dispenser is between 5 and 75% of the length of carrier pipe, with many holes of various diameters. Following steps should be achieved: a) carrier pipe is lowered into lava source in such a way so its upper part is 1-2 m above the lava level; b) gas is injected into dispenser until lava inside the carrier pipe is saturated; c) carrier pipe in lowered into lava source with overflowing of lava into lava source and is kept this way until lava inside carrier pipe is uniformly saturated by gas; d) steps a)-c) are repeated until start of steady motion of lava inside the whole carrier pipe; e) along with stabilization of the flow velocity of the gas saturated lava from carrier pipe, lava lifting process changes to steady-state conditions, for which purpose carrier pipe is installed in specified depth with previous air-tight connection to the receiving system in the surface and fumarole gas trap system—it is used as incombustible gas for injection into dispenser.

PERTINENT ART

Invention relates to the mining industry and may be used for lava extraction from magma lakes, located in the crater of active volcanoes, in the cavity of sleeping volcanoes or near them, both with and without exit to the surface.

PRIOR ART

There is available method for lifting of magmatic lava to the surface from the magmatic lava source—volcano—with the help of excavation machine, consisting of power shovel and bucket conveyor. In accordance with available method, one part of the excavation machine is installed outside the volcano and the other part is lowered inside the volcano, while the conveyor moves buckets so that the lower bucket scoops lava and moves it from the crater to the site outside the volcano (RU 2006103014 A, 20, Aug. 2007).

Shortcomings of available method amount to high hazard for personnel and limited depth of magmatic lava extraction.

There is available method for lifting magmatic lava to the surface from magmatic lava source—volcano—with the help of pipes and pumps (RU 2006103014 A, 20, Aug. 2007).

Shortcomings of this method also amount to its limited capacity due to underestimation of particular features of magmatic lava, characterized by high temperature and viscosity which make difficult application of convenient pumps, as well as controllability and steadiness of operation in lifting magmatic lava to the surface.

SUMMARY OF THE INVENTION

Technical result of the invention is improvement of its efficiency by increasing of magmatic lava lifting depth, providing safety, steadiness and controllability of the lifting operations for further lava processing.

Necessary technical result is achieved because lifting method is characterized by application of carrier pipe for the lifting of lava and a smaller diameter pipe for injection of incombustible gas, connected to the carrier pipe by the dispenser on specified depth. Length of dispenser is between 5 and 75% of the length of carrier pipe, with many holes of various diameters. Technical result is achieved with the help of following steps:

a) carrier pipe is lowered into lava source in such a way so its upper part is 1-2 m above the lava level;

b) gas is injected into dispenser until lava inside the carrier pipe is saturated;

c) carrier pipe in lowered into lava source with overflowing of lava into lava source and is kept this way until lava inside carrier pipe is uniformly saturated by gas;

d) steps a)-c) are repeated until start of steady motion of lava inside the whole carrier pipe;

e) along with stabilization of the flow velocity of the gas saturated lava from carrier pipe, lava lifting process changes to steady-state conditions, for which purpose carrier pipe is installed in specified depth with previous air-tight connection to the receiving system on the surface and fumarole gas trap system—it is used as incombustible gas for injection into dispenser.

Additionally:

fumarole and/or incombustible gas from external source is additionally used for injection into dispenser;

gas for injection into dispenser contains vapour-gas mixture;

lifted in the carrier pipe lava is treated by ultrasonic and/or electrical discharges and, if necessary, additionally treated by controlled magnetic field;

dispenser is designed as cowl concentrically wrapped around carrier pipe, which is perforated inside the cowl and has flexible sleeves, directed to the pipe center. Sleeves are connected with some holes (perforations) and can move inside carrier pipe, in lava flow, in relation to its inner walls. Besides that, sleeves have holes for exit of injected from the cowl gas.

Essence of the invention amounts to the fact that gas-lift (air lift) is basically used for the lifting of magmatic lava, taking into account special lava features. Due to higher viscosity and inhomogeneous structure of magmatic lava as well as its high temperature, prior to steady-state process of lava lifting to the surface should be applied special methods for the start of lifting process with the help of device which provides volume saturation of magmatic lava by gas and/or gas-vapour mixture with simultaneous volume dispersion of the lava itself. Trials showed that volume saturation effect and simultaneous volume dispersion are achieved when dispenser's length is 5-75% of the length of carrier pipe with holes of various diameters. At this incombustible gas is used in all operation for lifting of magmatic lava which ensures necessary safety of the lifting due to exclusion of additional uncontrollable fire sources in danger area.

Vapour may be added to incombustible gas for further stabilization of gas saturation and dispersion processes in lifted lava. On the launching stage neutral gases may be used as incombustible gas, and after that fumarole gases, generated in lifted lava and trapped during its lifting from the source and/or surface transportation. It ensures localization of toxic gases and also steady temperature conditions in the operational area. If there is shortage of mentioned gases, may be used incombustible gases or mixtures from external sources—other facilities.

EMBODIMENT OF THE INVENTION

Method is embodied in the following way.

Gas-lift is lowered into magmatic lava source. For this is used carrier pipe for lava lifting and a smaller diameter pipe for injection of incombustible gas, connected to the carrier pipe by the dispenser on specified depth. Length of dispenser is between 5 and 75% of the length of carrier pipe, with many holes of various diameters. Following steps should be achieved:

a) carrier pipe is lowered into lava source in such a way so its upper part is 1-2 m above the lava level;

b) gas is injected into dispenser until lava inside the carrier pipe is saturated;

c) carrier pipe in lowered into lava source with overflowing of lava into lava source and is kept this way until lava inside carrier pipe is uniformly saturated by gas;

d) steps a)-c) are repeated until start of steady motion of lava inside the whole carrier pipe;

After that starts steady-state mode of lava lifting. For this purpose carrier pipe is installed in specified depth with previous air-tight connection to the receiving system in the surface and fumarole gas trap system—it is used as incombustible gas for injection into dispenser.

If necessary, additional fumarole and/or incombustible gas from external sources are used as injection gas—for example, fumarole gas from another magmatic lava source or combustion gases from processing facilities.

In the case of insufficient capacity of magmatic lava lifting, carrier pipe in treated by ultrasonic and/or electrical discharges.

For better effects of magmatic lava saturation by gas and dispersion of lava itself, dispenser is designed as cowl concentrically wrapped around carrier pipe. Carrier pipe is perforated inside the cowl and has flexible sleeves, connected to perforated holes, with possibility to move inside the carrier pipe, in lava flow, in relation to its inner walls. So volume gas saturation is achieved due to gas injection into magma from many holes with various diameters, located both on the carrier pipe's inner surface and on the sleeves.

Specific example of the method implementation.

There is lava lake of the Ploskiy Tolbachik volcano on Kamchatka. This lake is located directly at the crater western boundary and is a round pit with 300 meters diameter and depth up to 50 meters. Temperature of magmatic lava in the lake is about 1000° C.; lava is saturated by volcano gases. To start extraction of magmatic lava, at the crater's edges are installed supports for cable lines, with the help of which platform with hole is steadily lowered on the lava lake surface. Two pipe columns are lowered into magmatic lava through the hole—for example, pipes can be manufactured from shock-resistant ceramic reinforced material, able to withstand high temperatures (over 1500° C.). Then carrier pipe with 2-3 m diameter and reinforcing ribs is selected. It serves for lifting of magmatic lava. Pipe with smaller diameter—100-200 mm—is used for injection of incombustible gas or incombustible vapour-gas mixture. These pipes are installed in such a way that at the depth of 25 m they are connected by volumetric dispenser. Dispenser is designed as sleeves, placed both along inner surface of the carrier pipe and at an angle to lava flow, up to its central part in the carrier pipe, with holes of various diameters (4-10 mm), protected from intake of magma by the fine mesh. In the launching mode following steps should be performed:

a) exit hole of the carrier (lifting) pipe is lowered to the face of magma lake and immersed into lava source so its upper part is lm higher than the lava level;

b) incombustible gas—for example, nitrogen—is injected into dispenser until lava inside carrier pipe is saturated;

c) carrier pipe is lowered into lava source with overflowing of lava into lava source and is kept this way until lava inside the carrier pipe in uniformly saturated by gas;

d) steps a)-c) are repeated until start of steady motion of lava inside the whole carrier pipe;

After that starts steady-state mode of lava lifting. For this purpose carrier pipe is fixed at the depth of 35-50 m with previous air-tight connection to the receiving system in the surface and fumarole gas trap system—it is used as incombustible gas for injection into dispenser.

Dispenser is started with necessary capacity in steady mode.

For more effective start of the gas-lift and transferring operation in steady-state mode can be used dispenser, manufactured in accordance with c1.5 of the Definition. Tubes of this dispenser, crossing the carrier pipe cross-section, generate additional sources for the lava flow volumetric gas saturation. Since dispenser's tubes are fixed to the carrier pipe wall in such a way so they have a free end and can be elastically bent to the carrier pipe wall and return to original position, it ensures passage even for solid bits of magmatic rocks.

For improvement of lava passage through the carrier pipe and further lava processing, this method includes possible treatment of magmatic flow by controlled magnetic field, as well as electrical and ultrasonic treatments for lifted magmatic lava, for destruction of existing physical inhomogeneity.

Also, for accelerated launch of the device, may be used dispenser-accelerator in the form of “graphite” rods (by analogy with nuclear reactors), put from above into carrier pipe at the initial technological stage, where electrical discharges are passed among rods to “shake” magma.

After starting mode in the lifting pipe, carrier pipe is connected to the surface piping.

Receiving reservoir is installed near the carrier pipe exit hole; its bottom is inclined in the direction of conveying trough, designated for the lava surface transportation. Receiving reservoir should be equipped by gas-vapour separator and gas-vapour discharge system, as well as compressor for suction of fumarole gases.

In the design should be included suction of fumarole gases from magmatic lava with the help of compressor. As a result pressure in the receiving reservoir is lower than atmospheric pressure, which additionally aids lifting of magmatic lava and generation of fumarole gases. Amount of magmatic lava, lifted to the surface, is regulated by compressor operation through increased or decreased volume of pumped into dispenser incombustible gas.

To lower or prevent intake of “non-processed” and “outsized” solid bits of magmatic rock into gas-lift carrier pipe, on the lifting pipe entrance should be installed mechanical conical filter.

INDUSTRIAL APPLICABILITY

The invention is applied for extraction of magmatic lava from magma lakes located in the crater of active volcanoes, in the cavity of sleeping volcanoes or near them, both with and without exit to the surface. 

1.-5. (canceled)
 6. A method for lifting of magmatic lava to the surface, comprising the steps of: a) providing a carrier pipe for lava lifting and a smaller diameter pipe for injection of an incombustible gas, wherein the smaller diameter pipe is connected to the carrier pipe by a dispenser of a specified depth, wherein a length of the dispenser is between 5% and 75% of a length of carrier pipe, wherein the dispenser includes a plurality of holes of various diameters; b) lowering the carrier pipe into a lava source such that an upper part thereof is 1 to 2 meters above the lava level; c) injecting a gas into the dispenser until the lava inside the carrier pipe is saturated; d) lowering the carrier pipe into the lava source so as to cause an overflow of lava into the lava source until the lava inside the carrier pipe is uniformly saturated by the gas; e) repeating steps b) through d) until a start of a steady motion of lava inside the whole carrier pipe occurs; wherein, along with stabilization of a flow velocity of the gas saturated lava from the carrier pipe, the lava lifting method changes to a steady-state condition, wherein the carrier pipe is installed in a specified depth with an air-tight connection to a receiving system on the surface and a fumarole gas trap system operable to be used as the incombustible gas for injection into the dispenser.
 7. The method according to claim 6, further comprising the step of using fumarole or the incombustible gas from an external source for gas injection into dispenser.
 8. The method according to claim 6, further comprising the step of using of a vapour-gas mixture in the injection gas.
 9. The method according to claim 6, further comprising the step of using an ultrasonic or electrical discharge treatment of the lifted lava in the carrier pipe.
 10. The method according to claim 6, wherein the dispenser is designed as a cowl concentrically wrapped around the carrier pipe that is perforated inside the cowl and has a flexible sleeve inside, and connected to the holes with the ability to bend inside the carrier pipe in the lava flow in relation to its inner walls. 